FIG. 30(a) is a perspective view showing a prior art. FIG. 30(b) is a plan view of the prior art of FIG. 30(a) seen from above. FIG. 30(c) is a plan view of the prior art of FIG. 30(a) seen from below. FIG. 31(a) is a perspective view showing the prior art. FIG. 31(b) is a disassembled perspective view of the prior art of FIG. 31(a). FIG. 31(c) is a plan view of the prior art of FIG. 31(a) seen from above. FIG. 31(d) is a plan view of the prior art of FIG. 31(a) seen from below. FIG. 32(a) is a perspective view showing the prior art seen from the back side. FIG. 32(b) is a partial enlarged perspective view of the back surface of FIG. 32(a). FIG. 33 is a perspective view showing the prior art of the present invention.
As prior art, as structures of a link member of the band, (1) a structure obtained by press-forming or forging, cutting, etc. (below, called “solid type”), (2) a structure combining solid members (below, called “separate type”), (3) a structure obtained by stamping, bending, forming, and otherwise press-forming a sheet member (below, called “sheet metal type”), (4) a structure obtained by wrapping a sheet member around an integrally formed link member (below, called “wrap around type”), etc. are known.
In a watch band etc., as the link members to be connected, ones with a solid feel and heavy appearance are preferred. For this reason, as shown in FIGS. 30(a) to (c), “solid type” link members 110 where the outside link parts 102 and middle link parts 103 are integrally formed by press-forming, forging, etc. are known. In recent years, the need has arisen for increasing the design variations of watches themselves by design of the watch cases or watch bands. For this reason, to make the outside link parts 102 and the middle link parts 103 visually appear to be formed by separate members, it has been sought to treat the outside link parts 102 and the middle link parts 103 by different surface treatment or processing so create a luxury feel at the band. However, in the integrally formed “solid type”, it was not possible to inexpensively and easily make the outside link parts 102 and middle link parts 103 appear to be separate members. Further, since the outside link parts 102 and the middle link parts 103 are treated by separate surface treatment or processing, the processing costs become high. For this reason, with a “solid type” link member 110, it was not that possible to obtain a high quality feel.
To deal with such a problem, as shown in FIGS. 31(a) to (d), a “separate type” link member 120 combining solid members is known. In this case, outside link parts 122 and middle link parts 123 are separately fabricated and then combined. As shown in FIG. 31(b), two outside link parts 122 positioned at the outsides in the width direction are connected by a connecting piece 125 at the back side. The middle link part 123 is provided with a step part 124 fitting with the connecting piece 125. A pin 160 is used to insert a pin into a pin hole 170 of the middle link part 123 to join the outside link parts 122 and the middle link part 123. Due to this, the outside link parts 122 and the middle link part 123 can appear as separate members and a heavy appearance with a solid feel can be obtained, so the look is excellent. However, with a complicated link shape where the two outside link parts 122 and connecting piece 125 are integrally formed, high precision, costly processing has to be performed and the processing processes end up becoming numerous and troublesome, so sometimes stable quality could not be obtained.
As opposed to this, with the “sheet metal type”, the parts assembled by manual work are reduced and costs are lowered, so numerous prior art are known such as PLTs 1 to 5 etc. In PLT 1, each link member to be connected is comprised of a single sheet folded into three layers to obtain an appearance of a solid member. The side surfaces in the band width direction are polished so that the boundaries of the superposed sheet pieces do not stand out, but still the high quality image of a solid member cannot be obtained. Further, wrapping pieces connecting the link members with each other had seams at the back surfaces, so there was the problem of burrs of the seams scratching the arm. PLT 2 also has parts at the back surfaces of the link members where recessed/projecting parts are engaged so there are problems similar to PLT 1.
In PLT 3 as well, steps are taken to prevent the bent and joined parts from being visible, but in the same way as PLT 1, the boundaries of the superposed sheet pieces are exposed at the side surfaces in the band width direction and a solid, high quality image could not be obtained. In PLT 4, each link member to be connected is comprised of a single sheet with front end edges engaged to strengthen the connection, then the seam of the front edges is covered by separate sheets sandwiching the sheet pieces from the top and bottom and welding them together, but again, problems similar to PLT 1 occur. PLT 5 also has the boundaries of superposed sheet pieces exposed at the side surfaces in the band width direction and thereby have problems similar to PLT 1.
To solve such problems, as the “wrap around type” where sheet members are wrapped around the link members, the watch bands of FIG. 32 and FIG. 33 are known. This type is comprised of a plurality of solid type links shown in FIG. 30 in which middle link parts are wrapped around by single sheet members. As shown in FIG. 32 and FIG. 33, the end parts of the sheet members wrapped around the middle link parts appear as seams at the back (under, bottom) surfaces, so there is the problem that the angles or burrs of the end parts will scratch the skin of the arm when a watch is worn. Since there were seams at the back surfaces, there was little of a high quality feeling in the appearance.
As something close to a “wrap around type”, PLT 6 discloses a case-side link positioned at one end part of the watch band. This case-side link is attached to a band mount at a watch case. A link body made of plastic is covered by a cover member made of stainless steel or another metal sheet in this configuration. However, the two end parts of the cover member are present at the back surface of the case-side link, so there are problems similar to the watch band of FIG. 32 and FIG. 33.